This is about the headphone-internal volume control, correct?
Generally i expect most people keep their devices (be it BT or USB-C dongles) at 100% internal volume and use the OS controls as normal - and that this is fine in almost all cases.
My shokz headphones set their internal volume to 0 when charging under certain circumstances - so i use btvol to fix that -and i always max them out. I think i even read someone having replaced btvol with just calling voicemail.